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Hormone therapy for secondary breast cancer

Hormones such as the female sex hormones, oestrogen and progesterone, can make some breast cancer cells divide and grow. So drugs that block the action of hormones, or change the levels in the body, can treat some secondary breast cancers. Hormone therapies can stop or slow down the development of the cancer cells and can reduce symptoms. Hormone therapy seems to work best with oestrogen receptor positive cancers, and slow growing cancers affecting the bones or the skin.

Tamoxifen is a type of hormone therapy. It can help many women with secondary breast cancer, whether or not they have had the menopause. Aromatase inhibitors are another type of hormone therapy and are mainly used to treat postmenopausal women. The different hormone therapy drugs have different side effects.

Progesterone

Artificial progesterone can control the growth of some breast cancer cells. If aromatase inhibitors or tamoxifen stop working, your doctor may suggest progesterone treatment instead. You can have it as tablets or by injection.

Switching off your ovaries

If you have not yet had your menopause and have secondary breast cancer, your specialist will probably suggest treatment that stops your ovaries making oestrogen. You may have surgery to remove your ovaries, radiotherapy to the ovaries, or monthly injections with a drug called goserelin (Zoladex). All these treatments give you an early menopause, which causes menopausal symptoms. There are ways of reducing the menopausal symptoms.

What hormone therapy is

Some hormones, such as the female sex hormones oestrogen and progesterone, can make some breast cancer cells divide and grow. So some treatments for secondary breast cancer use drugs that block the action of these hormones, or change the levels in the body. Hormone therapies can stop or slow down the development of the cancer cells and can reduce symptoms.

Hormone therapy seems to work best for women who have oestrogen receptor positive cancers. Some breast cancer cells have specific proteins called oestrogen receptors. When oestrogen molecules attach to the receptor, it stimulates the cell to grow into two new cells. Tests can show whether your breast cancer cells are oestrogen receptor positive (ER positive).

Hormone therapy also works well for women with slow growing breast cancers affecting the bones or the skin.

Advantages of hormone therapy

Hormone therapies tend not to cause bad side effects. Although side effects may be a problem, they are not often serious. Another advantage is that there are many different hormone treatments. So your doctor may try different ones until they find one that works and suits you best.

The main types of hormone therapy used for secondary breast cancer are covered below.

In women who have had their menopause the body makes oestrogen by a process known as aromatisation. Sex hormones (androgens) produced by the adrenal glands are turned into oestrogen in the fatty tissue of the body. The adrenal glands are small glands just above the kidneys. A chemical called aromatase changes the androgens into female hormones.

Aromatase inhibitors block aromatisation, and lower the level of oestrogen in the body. So the hormone receptors are exposed to less oestrogen and the cancer cells receive fewer signals to divide. Aromatase inhibitors are currently mainly used for postmenopausal women. But research is being carried out into using them in premenopausal women who have been put into a temporary menopause by using another hormonal therapy called Zoladex.

There are several different aromatase inhibitors used to treat secondary breast cancer and you take them as tablets once a day. They include

The links above take you to information about the individual drugs and their side effects.

Aminoglutethimide is another aromatase inhibitor that is rarely used now. It switches off natural steroid production as well as oestrogen production. So you have to take steroid replacement tablets all the time you are taking aminoglutethimide.

If you have not had your menopause, you have already had tamoxifen, and your cancer has come back or continued to grow, then your doctor will offer treatment to switch off your ovaries.

If you are a man with advanced ER positive breast cancer, then your doctor will offer tamoxifen unless you have had tamoxifen treatment before.

Tamoxifen is a commonly used hormone therapy. Many people have taken tamoxifen as treatment for primary breast cancer. It can also help many people with secondary breast cancer. There is a liquid type called Soltamox.

The main side effects of tamoxifen include hot flushes and sweats, changes to your periods, painful joints, and feeling sick. To find out more about the side effects of tamoxifen look in the section about cancer drugs.

Fulvestrant (Faslodex)

Fulvestrant (Faslodex) is a type of hormone therapy called an oestrogen receptor antagonist. Doctors can prescribe it for postmenopausal women with advanced breast cancer that is oestrogen receptor positive. They usually use it if tamoxifen or aromatase inhibitors are no longer controlling the cancer.

Fulvestrant works in two ways. Firstly, it blocks oestrogen receptors, in a similar way to tamoxifen. But it can also change the shape of oestrogen receptors in the cancer cells, so the oestrogen can’t attach to them. This is called down regulation.

You have fulvestrant as an injection into a muscle (an intra muscular injection) two weekly for 3 doses and then once a month. You may have some soreness and swelling around the injection site for a day or 2 afterwards. Side effects are usually mild but can include weakness, feeling sick, and changes in how your liver works.

Progesterone (Megace or Provera)

Progesterone is another hormone that occurs naturally in women. Artificial progesterone can control the growth of breast cancer cells. You can have it as tablets or by injection. The most common types of progesterone are

Switching off your ovaries

If you have not yet had your menopause and have secondary breast cancer, your specialist will probably suggest treatment called ovarian ablation. This stops your ovaries producing oestrogen. There are several ways to stop your ovaries working

Goserelin is a hormone treatment. You have it as monthly injections. It works on the part of the brain that stimulates the ovaries to produce oestrogen. The drug switches the ovaries off. This treatment is reversible. If you stop the injections, your ovaries should start working again. But, the closer you are to the age when your menopause will start and the longer you take goserelin, the more likely it is that it will stop your ovaries working permanently.

Early menopause

All the treatments that stop your ovaries working give you an early menopause (even though this may be temporary with goserelin). Some women find this very difficult to deal with. You are likely to have menopausal symptoms that start very suddenly. You may find it helpful to look at our information about coping with menopausal symptoms due to breast cancer treatment.

Most doctors are sensitive to a woman’s feelings about this type of treatment. You may want time to think about the pros and cons of the treatment and whether you would prefer permanent or temporary ovarian ablation. You may want to go home and talk it over with your family and friends before deciding to go ahead.

Finding information and support

You can phone the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday. They will be happy to answer any questions that you have.

If you would like to talk to someone outside your own friends and family, some organisations can put you in touch with counselling services. You can find these on our breast cancer organisations page. To find out more about counselling look at the counselling section.

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